title: Targeted DNA demethylation and activation of endogenous genes using programmable TALE-TET1 fusion proteins.
abstract: Genome-wide studies have defined cell type-specific patterns of DNA methylation that are important for regulating gene expression in both normal development and disease. However, determining the functional significance of specific methylation events remains challenging, owing to the lack of methods for removing such modifications in a targeted manner. Here we describe an approach for efficient targeted demethylation of specific CpGs in human cells using fusions of engineered transcription activator-like effector (TALE) repeat arrays and the TET1 hydroxylase catalytic domain. Using these TALE-TET1 fusions, we demonstrate that modification of critical methylated promoter CpG positions can lead to substantial increases in the expression of endogenous human genes. Our results delineate a strategy for understanding the functional significance of specific CpG methylation marks in the context of endogenous gene loci and validate programmable DNA demethylation reagents with potential utility for research and therapeutic applications.
authors.affiliation: 1] Department of Pathology and Center for Cancer Research, Massachusetts General Hospital, Charlestown, Massachusetts, USA. [2] Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, Massachusetts, USA. [3] Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts, USA. [4].
authors.forename: Morgan L
authors.initials: ML
authors.lastname: Maeder
authors.forename: James F
authors.initials: JF
authors.lastname: Angstman
authors.forename: Marcy E
authors.initials: ME
authors.lastname: Richardson
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Linder
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Cascio
authors.forename: Shengdar Q
authors.initials: SQ
authors.lastname: Tsai
authors.forename: Quan H
authors.initials: QH
authors.lastname: Ho
authors.forename: Jeffry D
authors.initials: JD
authors.lastname: Sander
authors.forename: Deepak
authors.initials: D
authors.lastname: Reyon
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Bernstein
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Costello
authors.forename: Miles F
authors.initials: MF
authors.lastname: Wilkinson
authors.forename: J Keith
authors.initials: JK
authors.lastname: Joung
mesh_terms: D019175:DNA Methylation / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D018390:Gene Targeting / Q000379:methods*; D006801:Humans; D006899:Mixed Function Oxygenases; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D006899:Mixed Function Oxygenases; C462539:TET1 protein, human